Musculoskeletal and Endocrine Pathologies: Arthritis, Spondylitis, and Hormonal Disorders

Posted on Nov 1, 2025 in Human Biology

Joint and Musculoskeletal Disorders

Osteoarthritis (OA)

Degeneration of weight-bearing and finger joints.

Types of Osteoarthritis

  • Primary: Associated with weight-bearing stress, obesity, and aging.
  • Secondary: Follows trauma or repetitive use.
  • Genetics play a role in susceptibility.

Pathological Changes in OA

  1. Articular cartilage is damaged, leading to the release of enzymes.
  2. This accelerates cartilage disintegration. Subchondral bone is exposed, leading to the development of cysts, osteophytes, or new bone spurs.
  3. Cartilage breaks into the joint space, causing the joint space to narrow.
  4. Secondary inflammation occurs, resulting in pain with weight-bearing and use.

Manifestations of OA

  • Pain and decreased joint movement or activity.
  • Increased fall risk.
  • Temporomandibular Joint (TMJ) syndrome, causing difficulty swallowing or speaking.
  • Bone enlargement of distal interphalangeal joints.

Treatment for OA

  • Physiotherapy and Occupational therapy.
  • Glucosamine chondroitin supplements.
  • Synthetic synovial fluid injection (to decrease degeneration).
  • NSAIDs (to decrease inflammation).
  • Arthrotomy to stabilize the joint (to increase joint space).
  • Joint replacement surgery.

Rheumatoid Arthritis (RA)

An autoimmune disorder causing chronic systemic inflammatory disease. Affects women more than men and impacts all age groups.

Pathological Changes in RA

  1. Synovitis (inflammation of the synovium) occurs.
  2. Pannus (granulation tissue) spreads.
  3. Cartilage erosion leads to an unstable joint.
  4. Fibrosis occurs: the joint space calcifies and obliterates (narrows).
  5. Ankylosis results in joint fixation and deformity, leading to loss of movement.

Joint Manifestations of RA

  • Inflammation (often starting in the hands): joints are red, swollen, sensitive, and painful.
  • Joint stiffness and impaired joint movement.
  • TMJ involvement (condyle damaged) leading to malocclusion (bad bite) of teeth.

Systemic Manifestations of RA

  • Fatigue, depression, malaise, anorexia, and low-grade fever.
  • Resistant iron deficiency anemia (related to the immune system response).

Treatment for RA

  • Balance rest and activity.
  • Physical and occupational therapy.
  • NSAIDs and Glucocorticoids (to decrease inflammation).
  • Disease-modifying antirheumatic drugs (immunosuppressants).
  • Biologic response modifying agents (to decrease autoantibody production).

Ankylosing Spondylitis (AS)

A chronic, progressive, inflammatory condition primarily affecting the sacroiliac joints, intervertebral spaces, and costovertebral joints. Typically affects men aged 20–40 years. Cause is unknown, possibly autoimmune with a genetic basis.

Pathophysiology of AS

  1. Vertebral joints become inflamed.
  2. Fibrosis and calcification lead to the fusion of joints, resulting in a bamboo spine appearance.
  3. Lower back inflammation progresses to costovertebral calcification.
  4. Decreased rib movement leads to decreased lung expansion.

Manifestations of AS

  • Low back pain and morning stiffness.
  • The spine becomes progressively more rigid, potentially leading to loss of mobility.
  • One-third of patients develop fatigue, fever, and weight loss.
  • Uveitis, particularly iritis (eye inflammation), is common.

Endocrine Disorders: Thyroid Conditions

Graves Disease (Hyperthyroidism)

Caused by antibodies that mimic TSH, stimulating excessive thyroid hormone (TH) release.

  • Signs and Symptoms: Sweating, fast or irregular heart rate (HR), anxiety, weight loss, and Exophthalmos (bulging eyes).

Endemic Goiter (Hypothyroidism)

Hypothyroidism caused by decreased iodine levels in soil and food.

  • Signs and Symptoms: Dysphagia (difficulty swallowing), lump in the neck, and hoarseness.

Congenital Hypothyroidism

Characterized by decreased growth and brain development.

  • Signs and Symptoms (Cretinism): Protruding tongue, decreased growth and reflexes, jaundice, dry skin, and hoarseness.

Hashimoto Thyroiditis

The thyroid is destroyed by antibody-dependent or cell cytotoxicity.

  • Signs and Symptoms: Goiter (if iodine intake is low), cold intolerance, increased BMI, lethargy, decreased appetite, and myxedema.

Endocrine Disorders: Growth Hormone (GH) Abnormalities

Dwarfism

Deficiency in Growth Hormone (GH) production and release.

  • Tumors can cause pituitary agenesis.
  • Laron-type dwarfism is a hereditary defect in Insulin-like Growth Factor (IGF) production.

Gigantism

Increased GH secretion occurring before puberty and epiphysis (growth plate) fusion.

Acromegaly

Increased GH secretion in adults.

  • Bones become broad and heavy, and soft tissue grows excessively.

Effects of Excess GH

  • Overgrowth of cartilaginous parts of the skeleton.
  • Enlarged heart and organs.
  • Metabolic disturbances: altered fat metabolism and decreased glucose tolerance (due to increased lipolysis).